A Cloudflare Error 1200 indicates that Cloudflare’s edge network has queued too many pending requests waiting for an origin web server that is responding too slowly to keep up with incoming traffic.
Common causes
There are too many requests queued on Cloudflare’s edge that are awaiting process by your origin web server. This limit protects Cloudflare’s systems.
Resolution
Tune your origin web server to accept incoming connections faster. Adjust your caching settings to improve cache-hit rates so that fewer requests reach your origin web server. Reach out to your hosting provider or web administrator for assistance.